Cross-site scripting (XSS) vulnerability in Microsoft Office SharePoint Server 2010 Gold and SP1, and SharePoint Foundation 2010, allows remote attackers to inject arbitrary web script or HTML via the URI, aka "XSS in SharePoint Calendar Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12835
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-074